A new generation of skin patches could be used to treat a range of conditions from diabetes to depression. They were first used to help smokers quit and boost hormone levels in women going through the menopause but in recent years skin patchess have been recommended for a variety of medical conditions.

Ailments from allergies and asthma to diabetes and even prostate cancer could soon be treated simply by sticking a patch on the arm, back or tummy. Scientists are even working on electronic patches with tiny power packs that can force drugs through the skin and into the blood. Patches were first introduced in the Eighties as a way of improving how medicines are delivered into the body. When we swallow pills they must be absorbed through the stomach into the bloodstream before they can start working. This means all of the active drug enters the system at the same time, leading to peaks and troughs in the levels circulating in the body.

However patches gradually release drugs through the skin, keeping levels in the blood constant which leads to more effective treatment of symptoms. Nowadays they are increasingly being used for pain and motion sickness as well as nicotine and hormone replacement therapy.

Scientists are also working on a new generation of patches that could transform the way we take drugs.

Peanut allergiesA stick-on patch packed with tiny traces of peanut protein could help thousands of people affected by life-threatening allergies to the popular snack.

Worn on the arm or back the patch allows minute amounts of the protein to gradually seep through the top layers of the skin. It then comes into contact with immune system cells which would normally trigger a life-threatening overreaction in someone who is allergic. The proteins however are in such tiny quantities that the immune cells slowly get used to their presence, learning to recognise peanuts so that they are no longer a threat. As a result the body's defences stop overreacting when they come into contact with peanuts.The patch, about the size of a 10p piece, is being developed in France and recently entered a year-long international trial involving more than 200 patients with severe peanut allergies.

IncontinenceBritish doctors are trialling a new high–tech skin patch to tackle urinary incontinence, a condition that affects millions of women. Called VERV it is worn on the back and, using a remote control, the patient can switch it on so that it sends high frequency signals through the skin into the nerves that control the contraction of bladder muscles. It is waterproof and is worn for seven days before being swapped for another one. Tests show two-thirds of patients see at least a 50 per cent reduction in symptoms.

DiabetesA patch that delivers insulin into the body, instead of a patient needing daily injections, would be a major breakthrough in diabetes. The problem has always been that insulin molecules are too large to squeeze through the surface of the skin. Now a revolutionary new patch is being developed that uses sound waves to blast insulin through the skin.

The patient wears the patch on their upper arm and places a hand-held sonic applicator (about the size of a mobile phone) over it.At the press of a button it produces a burst of sound waves that prises open sweat glands and hair follicles, providing a direct route through to the bloodstream. The insulin is propelled through the pores of the skin and into the bloodstream in a matter of seconds.

At the press of a button it produces a burst of sound waves that prises open sweat glands and hair follicles, providing a direct route through to the bloodstream. The insulin is propelled through the pores of the skin and into the bloodstream in a matter of seconds.

The patch, called the U-Strip, has already undergone initial trials involving around 100 people in the US which suggest it can deliver insulin into the blood as quickly and effectively as a needle.

ShinglesPutting chillies on the skin might not sound like a cure for the pain of shingles but a skin patch containing the red hot flavouring could be the answer. US trials show wearing the patch just once for up to an hour can have an effect on pain, with the benefits lasting up to three months.

Shingles is an infection in the nerves, usually around the trunk, which causes a rash that is both itchy and extremely painful. About one in five people suffers from it at some time in their life.

A pain-busting chemical in chillies called capsaicin could be a solution. Capsaicin is already used in over-the-counter painkilling creams and gels for patients with osteoarthritis.

Alzheimer'sEven Alzheimer's disease could soon be treated with a patch that is worn on the neck. About the size of a matchbox it does not release medicine but instead works by stimulating the production of nitric oxide inside the carotid artery, the major artery running from the heart to the brain.

Nitric oxide is a gas that helps arteries to relax and become dilated so blood can flow more freely around the body. Studies suggest restricted blood flow to the brain may be a major factor in the development of Alzheimer's disease. Shining an infrared light through the neck stops the carotid artery from contracting. The patch, developed by US firm Clarimedix Inc, could be a drug-free way to combat the symptoms.

Since the patch contains no medicine and appears to have no side effects it would not have to undergo the same rigorous testing process as a drug. This means that if planned human trials are successful, it could be available for use within a few years.

Prostate cancerA patch containing minute amounts of nitro-glycerine, a chemical once used as a deadly explosive, could be an unlikely treatment for prostate cancer. Similar patches are already used for angina, a painful heart condition caused by blocked arteries.

British scientists have now discovered they could stop some tumours in their tracks by boosting nitric oxide. Previous studies have shown prostate tumours appear to thrive when there is an absence of nitric oxide.

Patients who took part in a small clinical trial at Queen's University Belfast saw their levels of prostate specific antigen, a chemical marker in the blood that increases when cancer is present, stabilise after wearing the patch 24 hours a day for two years.

DepressionCould a skin patch even tackle depression? Scientists have developed one similar in size to a nicotine patch that contains a drug shown to alter mood. Sticking the patch anywhere on the upper body (usually the trunk or arms) could be an alternative to the daily popping of pills for many people with depression.

Called EMSAM it has been licensed in the US for several years but is not yet available in the UK. The skin patch contains a drug called selegiline which is already used to treat Parkinson's disease but is also effective against depression. - Pat Hagan/Daily Express

AsthmaAn allergy to house dust mites is one of the major triggers for asthma but a new patch is being developed that could tackle the problem. It will be used on babies who have the allergy but have not developed full-blown asthma.

By exposing them to regular, tiny amounts of a protein found in house dust mites, scientists hope to "retune" the immune system so it does not overreact to its presence and cause inflammation in the airways. If it works it could be the first ever method for preventing asthma. (Pat Hagan/Daily Express)